These estimates based on revenue of $2-$4 per handset
worldwide. For perspective, Google generated $1/year per
global installed PC ($6 in US) in 2002 and that number has since
risen to $19 ($37 in US)

The larger opportunity in years 4 and 5 could come from
software/application and hardware royalties.

Assuming Google successfully attracts hundreds of millions of
mobile users (not a given but not unreasonable in light of
Google's worldwide dominance), Aggarwal's per-phone assumptions
seem reasonable. This would basically require only about
one incremental search and click per user per month. An
extra $2-$5 billion would increase Google's current revenue base
($16 billion) by 15%-30%.